1. Field
The present invention relates to a radio equipment control, radio equipment and a communication system to perform communications in a base station.
2. Description of the Related Art
A base station in a radio communication system that includes cellular phones or the like may be divided into RE (Radio Equipment), which processes radio signals, and REC (Radio Equipment Control), which controls the REs (RE units). For example, CPRI (Common Public Radio Interface) is known as an interface for connecting REC and REs. By using CPRI, the base station can be divided into REs and REC, and setting the interface is made open to users, whereby respective sections in the base station can be multivendored. CPRI defines layer1 (L1) and layer2 (L2) based on hardware as an application range.
There has been known a connecting arrangement between REC and REs in which REC has plural CPRIs and each CPRI is connected to RE in one-to-one style. Furthermore, there is known a connecting arrangement in which REs are cascade-connected (for example, refer to paragraph 0046 and FIG. 11 of Japanese translation of PCT international application No. 2007-511955). In the cascade connection of REs, REC and RE at the first stage are connected to each other through CPRI, and RE and RE at subsequent stages are connected to each other through a connection unit inherent to the device.